- Solder capacitors C5 (220uF) and C6 (.1uF, marked 104) and resistor R4 (1m, Brown Black Green; resistor body may be blue in your kit).
- Make sure C5's polariy matches its footprint, just like C1.
- Wire speaker to LS1.
- Thread remaining ribbon cable through hole.
- Strip insulation and solder to LS1.
- Strip and solder the other ends to the speaker, matching the "+" and "-" sides.
- Solder socket U2. Match its dimple to the footprint, just like U1.
- With the power off, carefully insert LM386 chip, again making sure its inserted the correct way.
Power on, unplug your headphones, and press the switch. It should be playing out of the speaker now. Power off.
Not working as expected? Check the PCB troubleshooting section. Otherwise, continue to the next step.